Early Results from VLT-SPHERE: Long-Slit Spectroscopy of 2MASS 0122-2439B, a Young Companion Near the Deuterium Burning Limit

Abstract

We present 0.95-1.80 $\mu$m spectroscopy of the $\sim$12-27 $M_{\mathrm{Jup}}$ companion orbiting the faint ($R$$\sim$13.6), young ($\sim$120 Myr) M-dwarf 2MASS J01225093--2439505 ("2M0122--2439 B") at 1.5 arcsecond separation (50 AU). Our coronagraphic long-slit spectroscopy was obtained with the new high contrast imaging platform VLT-SPHERE during Science Verification. The unique long-slit capability of SPHERE enables spectral resolution an order of magnitude higher than other extreme AO exoplanet imaging instruments. With a low mass, cool temperature, and very red colors, 2M0122-2439 B occupies a particularly important region of the substellar color-magnitude diagram by bridging the warm directly imaged hot planets with late-M/early-L spectral types (e.g. $\beta$ Pic b and ROXs 42Bb) and the cooler, dusty objects near the L/T transition (e.g. HR 8799bcde and 2MASS 1207b). We fit BT-Settl atmospheric models to our $R$$\approx$350 spectrum and find $T_{\mathrm{eff}}$=1600$\pm$100 K and $\log (g)$=4.5$\pm$0.5 dex. Visual analysis of our 2M0122-2439 B spectrum suggests a spectral type L3-L4, and we resolve shallow $J$-band alkali lines, confirming its low gravity and youth. Specifically, we use the Allers & Liu (2013) spectral indices to quantitatively measure the strength of the FeH, VO, KI, spectral features, as well as the overall $H$-band shape. Using these indices, along with the visual spectral type analysis, we classify 2M0122-2439 B as an intermediate gravity (INT-G) object with spectral type L3.7$\pm$1.0.

arXiv commentAccepted to ApJ Letters, 8 pages, 4 figures, some minor typographical issues were fixed

References in corpus (37)

• Evolutionary models for very-low-mass stars and brown dwarfs with dusty atmospheres
• A Method of Correcting Near-Infrared Spectra for Telluric Absorption
• Images of a fourth planet orbiting HR 8799
• The Gemini Planet Imager: First Light
• The Evolution of L and T Dwarfs in Color-Magnitude Diagrams
• A Giant Planet Candidate near a Young Brown Dwarf
• An Infrared Spectroscopic Sequence of M, L and T Dwarfs
• Clouds and Chemistry in the Atmosphere of Extrasolar Planet HR8799b
• A Near-Infrared Spectroscopic Study of Young Field Ultracool Dwarfs
• On the age of the $\beta$ Pictoris moving group
• Bayesian analysis to identify new star candidates in nearby young stellar kinematic groups
• The NIRSPEC Brown Dwarf Spectroscopic Survey. I. Low-Resolution Near-Infrared Spectra
• Discoveries from a Near-infrared Proper Motion Survey using Multi-epoch 2MASS Data
• Masses, Radii, and Cloud Properties of the HR 8799 Planets
• The Tucana/Horologium, Columba, AB Doradus, and Argus Associations: New Members and Dusty Debris Disks
• The Extremely Red, Young L Dwarf PSO J318-22: A Free-Floating Planetary-Mass Analog to Directly Imaged Young Gas-Giant Planets
• Discovery of a Very Young Field L Dwarf, 2MASS J01415823-4633574
• Characterizing Young Brown Dwarfs using Low Resolution Near-IR Spectra
• The Spectroscopically Determined Substellar Mass Function of the Orion Nebula Cluster
• Discovery of a Low-Mass Brown Dwarf Companion of the Young Nearby Star G196-3
• First Light LBT AO Images of HR 8799 bcde at 1.65 and 3.3 Microns: New Discrepancies between Young Planets and Old Brown Dwarfs
• HD 203030B: an Unusually Cool Young Sub-Stellar Companion near the L/T Transition
• A New High Contrast Imaging Program at Palomar Observatory
• Three Wide Planetary-Mass Companions to FW Tau, ROXs 12, and ROXs 42B
• A Multiplicity Survey of the Rho Ophiuchi Molecular Clouds
• Direct Imaging and Spectroscopy of a Candidate Companion Below/Near the Deuterium-Burning Limit In The Young Binary Star System, ROXs 42B
• Temporal Evolution of Coronagraphic Dynamic Range, and Constraints on Companions to Vega
• A Disk Around the Planetary-Mass Companion GSC 06214-00210 b: Clues About the Formation of Gas Giants on Wide Orbits
• Planets Around Low-Mass Stars (PALMS). III. A Young Dusty L Dwarf Companion at the Deuterium-Burning Limit
• Gemini Planet Imager Spectroscopy of the HR 8799 planets c and d
• The First H-band Spectrum of the Massive Gas Giant Planet beta Pictoris b with the Gemini Planet Imager
• WISEP J004701.06+680352.1: An intermediate surface gravity, dusty brown dwarf in the AB Dor Moving Group
• The Kappa Andromedae System: New Constraints on the Companion Mass, System Age & Further Multiplicity
• Exoplanet characterization with long slit spectroscopy
• Speckle Suppression with the Project 1640 Integral Field Spectrograph
• Infrared Parallaxes of Young Field Brown Dwarfs and Connections to Directly Imaged Gas-Giant Exoplanets
• High-contrast spectroscopy of SCR J1845-6357 B

Cited by in corpus (21)

• SPHERE: the exoplanet imager for the Very Large Telescope
• Imaging Extrasolar Giant Planets
• Population Properties of Brown Dwarf Analogs to Exoplanets
• The Hawaii Infrared Parallax Program. II. Young Ultracool Field Dwarfs
• Discovery of a warm, dusty giant planet around HIP65426
• First light of the VLT planet finder SPHERE. IV. Physical and chemical properties of the planets around HR8799
• First light of the VLT planet finder SPHERE. II. The physical properties and the architecture of the young systems PZ Tel and HD 1160 revisited
• The GJ 504 system revisited. Combining interferometric, radial velocity, and high contrast imaging data
• The SPHERE infrared survey for exoplanets (SHINE) -- II. Observations, Data reduction and analysis Detection performances and early-results
• In-depth study of moderately young but extremely red, very dusty substellar companion HD206893B
• WISEA J114724.10-204021.3: A Free-Floating Planetary Mass Member of the TW Hya Association
• Obliquity Constraints on an Extrasolar Planetary-Mass Companion
• Rotation Periods, Inclinations, and Obliquities of Cool Stars Hosting Directly Imaged Substellar Companions: Spin-Orbit Misalignments are Common
• Discovery of Seven Companions to Intermediate Mass Stars with Extreme Mass Ratios in the Scorpius-Centaurus Association
• The JWST Early Release Science Program for the Direct Imaging & Spectroscopy of Exoplanetary Systems
• Using Data Imputation for Signal Separation in High Contrast Imaging
• Discovery of a low-mass companion around HR3549
• Characterising brown dwarf companions with IRDIS long-slit spectroscopy: HD 1160 B and HD 19467 B
• High-contrast observations of brown dwarf companion HR 2562 B with the vector Apodizing Phase Plate coronagraph
• Adaptive optics in high-contrast imaging
• Early evidence for isotropic planetary obliquities in young super-Jupiter systems